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Congenital Heart Disease - Fung Flashcards Preview

What is congenital heart disease?

1. General term used to describe abnormalities of the heart and great vessels that are present from birth2. Arise due to faulty embryogenesis during week 3 and 8 of gestation3. 1% of births have a congential cardiovascular defect and are the most common form of cardiovascular disease among children

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What are two general categories of causes of congenital heart diseases?

1. sporadic genetic abnormalities2. environmental factors

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What are some sporadic genetic abnormalities that may cause congenital heart disease?

Describe the clinical features of Tetralogy of Fallot.

1. Patients can survive into adulthood even untreated2. Clinical consequences are dependent on the degree of the subpulmonic stenosisMild: resembles an isolated VSD and more like a left to right shunt without cyanosis (pink TOF)Severe: Greater resistance to RV outflow and a right to left shunt (classic TOF)3. Pulmonary arteries become hypoplastic and aortic dilation4. Most patients are cyanotic at birth5. Complete surgical repair is possible

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What is Transposition of the great vessels (TOGV)?

1. Aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle Normally the aorta lies posterior to the pulmonary artery, but is reversed here 2. Defect develops due to abnormal formation of the truncal and aortopulmonary septa

What are the clinical features of TOGV?

Right ventricular hypertrophyAtrophic left ventricleWithout surgery most die within first months of lifeWith surgery can survive into adulthood

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What is persistent truncus arteriosus (PTA)?

1. Arises due to failure of separation of the embryological truncus arteriosus into the aorta and the pulmonary artery2. Single great vessel that receives blood from both ventricles and coronary circulation3. There is an associated VSD that produces systemic cyanosis and increased pulmonary blood flow (danger of irreversible pulmonary HTN)

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Describe Tricuspid Atresia.

1. Complete obstruction of the tricuspid valve orificeResults from unequal division of the AV canal resulting in an: Enlarged mitral valveUnderdeveloped right ventricle2. Right to left shunt through the atria (ASD, patent foramen ovale) and a VSD allows communication between the left ventricle and pulmonary artery that arises from a hypoplastic right ventricle3. Cyanosis is present at birth and very high mortality rate

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Describe total anomalous pulmonary venous circulation.

1. Pulmonary veins fail to directly join the left atrium due to the failure of the development (atresia) of the common pulmonary vein2. During fetal life primitive systemic venous channels drain from the lung into the left innominate vein or coronary sinus3. A patent foramen ovale or ASD allows pulmonary venous blood to enter the atrium

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What are the clinical features of total anomalous pulmonary venous circulation?

Volume and pressure overload leads to hypertrophy and dilation of the right heartDilation of the pulmonary trunkHypoplastic left atriumPossible cyanosis due to the right to left shunt of the ASD

This reversal is referred as late cyanotic congenital heart disease (Eisenmenger syndrome) and once irreversible pulmonary hypertension develops, structural defects are irreparable.

What are some examples of left to right shunts?

Describe atrial septal defect.

1. Abnormal fixed opening in the atrial septum caused by incomplete tissue formation that allows communication of blood between the left and right atria2. Not the same as a patent foramen ovale

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What are the three types of ASD?

1. Secundum (90%): result from deficient or fenestrated oval fossa near the center of the atrial septum2. Primum (5%): occur adjacent to the AV valves3. Sinus venosus (5%) occur near the entrance of the SVC and may be associated with anomalous pulmonary venous return to the RA

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What are the clinical features of ASD?

1. Left to right shunt due to lower pulmonary vascular resistance and greater distensibility of the RV2. Increased pulmonary blood flow produces a murmur3. Do not become symptomatic before age 30 and irreversible pulmonary HTN is unusual4. surgical or catheter based repair is possible and prevents complications

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What are some complications of ASD?

Describe a patent foramen ovale.

1. During fetal life the foramen ovale (a small hole in the atrial septum at the oval fossa) allows oxygen rich blood from the placenta to bypass the underinflated lungs2. After birth is forced shut due to increased blood pressure on the left heart in 80% of people3. In 20% of people during times of increased pressure on the right side (bowel movement, coughing, sneezing) the flap can open and can create a right to left shunt 4. There is a small possibility of a paradoxical embolism

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Describe a ventricular septal defect (VSD)?

1. Most common form of congenital cardiac anomaly, also common with Trisomy 212. Are associated with another congenital anomaly; only 20-30% occur in isolation3. Classified according to size and location

What are the clinical features of VSD?

Clinical manifestation depends on the size and associated right-sided malformation:1. Large VSD: Difficulties from birth Usually membranous or infundibular Cause significant left to right shuntingMust have early correction2. Small VSD: well tolerated and may close spontaneously

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Describe a patent ductus arteriosus.

1. In fetal circulation the ductus arteriosus shunts blood from the pulmonary artery to the aorta2. In PDA there is no spontaneous closure after birth3. Produces a harsh, machine like murmur4. 90% occur as an isolated anomaly5. 10% associated with VSD, coarctation of the aorta or pulmonic or aortic valve stenosis

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Describe the clinical features of patent ductus areteriosus.

1. Clinical features depends on the diameter and the cardiovascular status:Asympotmatic at birthNarrow PDA does not affect child’s growth and developmentLarger PDA start out as a left to right shunt but can lead to Eisenmenger syndrome2. Closure should happen in early life3. May keep open with prostaglandin E

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Describe an atrioventricular septal defect.

1. Also called atrioventricular canal defect2. Results from the embryologic failure of the superior and inferior endocardial cushions of the AV canal to fuse adequately3. Patients have incomplete closure of the AV septum and malformation of the tricuspid and mitral valves4. surgical repair is possible

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What are the forms of atrioventricular septal defect?

1. Partial ASVD: Primum ASVD and cleft anterior mitral leaflet leading to mitral insufficiency2. Complete ASVD: Large combined AV septal defect and a large common AV valve (hole in center of the heart)Communication of the four chambers leads to volume hypertrophy1/3 of patients have Down syndrome

Name the obstructive congenital heart diseases.

Describe coarctation of the aorta.

Common structural anomaly (narrowing of aorta)Associated with Turner syndrome (XO)

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What are the forms of coarctation of the aorta?

Infantile: Tubular hypoplasia of the aortic arch proximal to a patent ductus arteriosusSymptomatic in early childhoodAdult:Discrete ridgelike infolding of the aorta just opposite of the closed ductus arteriosus (ligamentum arteriosum) distal to the arch vessels

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Clinical manifestation of coarctation of the aorta depends on what?

The severity of the narrowing of the lumen and the patency of the ductus arteriosus:

Infantile form leads to manifestations early in life (right after birth)High mortality rate without surgical interventionDelivery of unsaturated blood through the PDA produces lower extremity cyanosis

Adult formChildren may go unrecognized until adulthood unless severeSymptoms includeHypertension in the upper extremitiesWeak pulses and hypotension in the lower extremitiesClaudication and coldness of lower extremitiesDevelopment of collateral circulation between pre and post coarctation arteries via enlarged intercostal and internal mammary arteries (notching seen on radiograph)Surgical repair possible

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Describe pulmonary stenosis.

Common malformationMay be isolated or be a part of a syndrome ( TOF, TGA)Resultant RVH Mild cases may be asymptomaticSevere cases require surgical repair

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Describe pulmonary atresia.

No communication between the right ventricle and lungsHypoplastic RV and ASDBlood reaches the lungs through a patent ductus arteriosus